Floodplain forests play many important roles in the fluvial processes and environments of large alluvial rivers, including acting as geomorphological influences and habitat for native fish during high flows. Many large, gravel-bed river systems have undergone substantial change in recent centuries, resulting in loss of forested area to agriculture, reduction...
Rainfall scarcity and variability present serious challenges to water security for many rural communities throughout the world's drylands. Sand dams--weirs built across ephemeral or seasonal rivers--provide an appropriate water harvesting and storage option for many regions. The structures quickly fill with sediment during rainy season flow events and store water...
Water temperature in rivers and streams is an important factor for aquatic ecosystem health. Measurement of stream temperature has traditionally been accomplished by point temperature measurements, continuous point temperature loggers, and more recently, airborne remote sensing techniques such as Forward-Looking Infrared Radar (FLIR) or Thermal Infrared Radiometry. While each of...
The objective of this study was to evaluate the use of aerial photos as a substitute for multiple-year pre-removal field data to assess the downstream channel changes associated with a small dam removal. The Brownsville Dam, a 2.1 m tall concrete dam on the Calapooia River, Oregon, was removed in...
The thermal regime of rivers plays a key role in aquatic ecosystem health. In the Willamette River, OR, the present day main channel temperature is often too warm for cold water fishes during the late spring, summer, and early fall. At these times, cold water fishes tend to be concentrated...
My thesis explored the effects of environmental variability on population
dynamics and community composition of aquatic insects. Environmental variability in
the form of flow regime in streams can limit the distribution and life-history traits of
aquatic insects. I used tributaries to the McKenzie River in Oregon with dramatically
different flow...
Surface water and groundwater are intimately connected by a two-way flux between the stream and the underlying aquifers; a complicated yet crucial relationship to represent in models. However, the National Water Model currently only considers a one-way flux, where groundwater can enter a stream but cannot return to the aquifer....
Excavations at the Cooper’s Ferry site (10IH73) revealed a long record of repeated human occupation extending from the late Pleistocene into the early Holocene (~16,000-10,000 cal BP) and have yielded unique insights into the Western Stemmed Tradition (WST), which includes. Several studies have focused on WST pit features encountered at...
Physical disturbance in streams has important effects on the metabolic rates of gross primary production (GPP) and ecosystem respiration (ER). Underlying lithology can control sediment size, amount, and evolution in the stream, influencing substrate stability and its effect on benthic organisms. We assessed the patterns of disturbance and recovery of...
The spatial and temporal variability of sediment transport processes in Oak Creek, OR was investigated and used to explore two study questions: 1) How do sediment transport processes influence benthic algal communities?, and 2) Can fluvial-hydraulic models make accurate predictions of bed load transport rates? Our study was conducted in...
Coho salmon (Oncorhynchus kisutch) migration and spawning are unique components of the salmon life cycle because they require synchrony of behavior with other individuals as well as with acceptable fluvial conditions. As with other organisms that exhibit group mating behavior, it is likely that environmental cues trigger coho salmon movement...
Published literature about six Pacific Northwest stream systems was contrasted
to provide a regional perspective on channel response to disturbance. This
investigation was prompted by a combination of recent environmental legislation,
mounting social pressures to plan projects at a drainage basin scale, and the difficulty
in defining and predicting the...
Sand dams – low-head dams built in ephemeral streambeds that store water within saturated sediments – are a proven means to increase water supplies for rural communities in arid and semiarid regions. Water percolates into the reservoir-impounded sediments during wet season rains and can subsequently be extracted during the dry...
Understanding the degree to which topography of erosional landscapes in active mountain belts encode the rates and patterns of active deformation in the upper crust is a primary goal in the field of tectonic geomorphology. In particular, the convolved influence of variations in rock mass quality and the erodibility of...
The nature of upper plate deformation along the Cascadia subduction zone (CSZ) is poorly understood. Systematic covariation among topographic relief, geodetically determined uplift rates, decadal to millennial erosion rates, and the frequency of episodic tremor and slip (ETS) along the Cascadia forearc suggest a genetic association between forearc topography and...
This study examined channel structure and position and riparian
vegetation and land use on the upper 70 km of the McKenzie River, Oregon in
the 1940s, compared the 1940s conditions to present conditions, and explored
the processes driving change in this system and the implications for aquatic
habitat. The hydrologic...
Analysis of topographic and river morphometric parameters was conducted using digital elevation models (DEMs) and field observations in order to determine the role of variable rock resistance on topographic relief, to examine how spatially and temporally variable rock uplift rates relate to river morphology, and to address the degree to...
Glaciers are effective reservoirs because they moderate variations in runoff and
supply reliable flow during drought periods. Thus, there needs to be a clear
understanding of the influence of glacier runoff at both the basin and catchment scale.
The objectives of this study were to quantify the late summer contributions...
In steep headwater basins of the Oregon Coast Range (OCR), debris flows episodically deliver material from low-order tributary basins to larger catchments. Much of this material is stored in valleys and gradually removed by fluvial processes. Quantifying the transfer of material from hillslopes to mainstem channels is essential in understanding...
Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris...
The composition and distribution of fish assemblages was examined in a
floodplain lake system in the Amazon basin. Quantitative samples were
collected during the 1992-1993 flooding season at Marchantaria Island, Solimoes
River. A total of 25,819 specimens representing 8 orders, 30 families, 101
genera and 139 species of fish were...
Management of small dams may have profound implications for the health and integrity of small rivers and freshwater diversity. Global indicators suggest future growth in the small hydropower sector, particularly in developing countries. As a renewable energy source, it is often presumed that small hydropower entails fewer and less severe...
Bar-pool morphology in rivers can provide vital habitat to aquatic species, notably salmonids, which require gravel riffles to bury eggs and pools for hydraulic and cold-water refuge. In some cases, the erosion and subsequent deposition of coarse sediment downstream of a dam removal can modify habitat by inundating bar-pool structure,...
Geomorphic change along the lower Clackamas River is occurring at
a millennial scale due to climate change; a decadal scale as a result River
Mill Dam operation; and at an annual scale since 1996 due to a meander
cutoff. Channel response to these three mechanisms is incision.
Holocene strath terraces,...
Sediment production and delivery in Pacific Northwest
coastal streams can have damaging effects on channel
morphology and anadromous fish habitat. The research in
Pistol River was designed to determine if a link exists
between sediment delivery processes and degradation of fish
habitat. Objectives of this basin-wide analysis were to:
1)...
This paper evaluates Oregon Statewide Planning Goal 5: Natural Resources and Goal 17
Coastal Shorelands, planning programs and makes recommendations for improvement to the
Oregon members of the Columbia River Estuary Study Task Force (CREST). CREST is a
Council of Governments formed in 1974 which includes the local counties, cities...
Nonpoint sources of pollution are being recognized
nationwide as a significant threat to groundwater quality.
In Oregon, groundwater supplies in several areas have been
affected by contamination possibly caused by nonpoint
sources associated with agricultural activities, on-site
sewage disposal, and inadequate hazardous materials
management in urban areas. State groundwater protection...
The nature and extent of niparian vegetation change from 1972 to
1981 in the Willamette River Greenway in Benton and Linn Counties,
Oregon was quantitatively investigated. The study was primarily by
aerial imagery analysis and associated field verification. A classification
of vegetation and land cover within the study area was...
In the face of climate change droughts are predicted to become more persistent, further intensifying the need for accurately predicting the timing and magnitude of summer streamflow in rivers. In order to determine the sensitivity of a watershed to drought, there is a need to describe what these drought conditions...
We monitored larval Lost River and shortnose suckers from natal beds in the Williamson and Sprague rivers to nursery grounds in Upper Klamath Lake. Downstream movements occurred at night, in the middle of the channel, and on the falling limb of the hydrograph. Ages, sizes, and developmental stages of larvae...
This investigation explored how the magnitude, style, and frequency of
channel adjustments vary spatially and over time within a 5th-order mountain
watershed. Historical data sets, including repeated cross section surveys spanning up
to 20 years at five sites on 2nd to 5th-order channels and streamflow records spanning
up to 50...
Studies of some components of test weight in Soft White wheat
revealed distinct subclass differences. Wheat kernels of Soft White
more completely occupied a given volume than did kernels of White
Club. The Soft White kernels were larger and had a higher density
than the White Club kernels. Because of...
I evaluated the response of the federally listed endangered plant species Bradshaw's desert parsley (Lomatium bradshawii) to livestock grazing and small mammal depredation at Oak Creek, Linn County, Oregon, 1997-1998. I established six study blocks (three each in wooded and herbaceous pastures) with plots in each block randomly assigned to...
The competencies of athletic coaches in selected Oregon
high schools were analyzed to determine the agreement among
various groups of coaches and principals as to what represents
success in high school coaching, and the agreement among groups
of selected coaches and principals in their assessment of the
importance of these...
Streamflow forecasts are essential to the optimal operation of
hydroelectric and irrigation reservoirs in the Pacific Northwest.
Satellite snow cover observations would aid in these streamflow forecasts
by providing snow cover data at regular time intervals. Unfortunately,
satellite capability to remotely sense mountain snow cover
conditions is indeterminate due to...
The object of this research study is to investigate and provide
some fundamental information about bed slumping in a partially defluidized
bed combustor. Due to the difficulty in making measurements and
observations at high temperature, a dynamically similar cold phase
fluidized bed was used to model the high temperature case....
Purpose: The purpose of this study was to determine the effectiveness, if any, of ten weeks of motor psychophysics training on the
development of dynamic muscular strength (as measured by the bench
press and squat) in male college athletes and non-athletes.
Procedures: This study was conducted during the first (spring)...
An approach to understanding and managing anadromous salmon, steelhead,
and sea-run cutthroat trout (Oncorhynchus spp.) based on life history and
evolutionary adaptive capacities of species and stocks is presented. Species, stocks,
and local populations are viewed as systems that are continuously adapting to
changing environmental conditions. They have the potential...
Coastal wetlands provide basic linkages between productive estuarine and freshwater ecosystems. Throughout the Mexican coast, rates of wetland loss and change are unknown. This project developed wetland inventories for 1973 and 1991, including ecological functions and values, and human activities in and around the wetlands. Data was integrated by use...
Patterns of resource partitioning among 4 sympatric sturnids: [black-collared starling (Sturnus nigricollis), pied starling (S. contra), common myna (Acridotheres tristis) and crested myna (A. javanicus) were determined based on their food habits, foraging and nesting microhabitat selection, morphology and behavior. The study was
conducted from March 1986 to June 1988...